Originally Posted by GoodVibrations
I don't think very much of it has to do with charisma, actually. Federer isn't naturally charismatic. It has more to do with marketing carving out a particular image/brand for an athlete and running with it. They realized that Federer could be marketed as this elegant, classy, Swiss gentleman (of course it helps that he's goat/among the goats). With Nadal, marketing could advance the image of him as a hardworking, never-say-die bull; his physical presence/persona speaks for itself. Neither one of those guys are especially charismatic in interviews.
Djokovic needs a niche as dictated by marketing more than anything else.
Tell me he doesn't have charisma.